Underreamer.



N0.8o9,57o. PATENTBDJAN.9,1906.

F.W.JONES.' UNDERREAMER.

' APPLICATION FILED AUG. 30. 1904.

NITED sTATns rATnNT or'ricn.

FREDERICK WV. JONES, OF SANTA PAULA, CALIFORNIA, ASSIGNOR TO EDVARD NORTH AND EDWARD DOUBLE, OF LOS ANGELES, CALI- FORNIA.

UNDERREAIVIER.

Patented Jan. 9, 1906.

Application filed August 30, 1904. Serial No. 222.688.

To all whom t may concern Paula, in the county of Ventura and State of California, have invented certain new and useful Improvements in Underreamers, of which the following is a specification.

This invention relates to underreamers for reaming out or enlarging well-holes under well-casings in the drilling of wells, and is more particularly designed for use in the drilling of oil-wells, the object of underreaming the hole below the well-casing being to enlarge the same in order to permit the casing to be lowered farther down.

The primary object of this invention is to provide an improved device of this class which shall be of extremely simple but durable construction, composed of few parts, simple and cheap to manufacture and assemble, and which shall be positive and eflicient in operation.

Other objects and ends in view will hereinafter appear from the detailed description of construction and operation.

The invention consists, primarily, of a mandrel having a central bore, a spring-actuated rod slidable in said bore, said rod provided at its lower end with a suitable head, said mandrel provided at its lower end with a chamber into which said vrod extends, said chamber having a lower cylindrical portion and an upper portion of less diameter, a beveled or inclined shoulder or abutment connecting said chamber portions and against which the bits or slips bear when in expanded position, and tilting slips carried on the head of said rod and provided with Shanks adapted to extend within said chamber portions, and with cutting portions extending out of said mandrel into suchwidth that when said bits are in extended position the spread of the same is greater than the diameter of said mandrel or of the well-casing, so that the hole cut by said expanded bits will be of greater diameter than the well-casing, the said bits or slips provided with beveled shouldersl adapted when said bits are pulled up into said chamber by said spring-actuated rod to come in contact with said beveled abutment and cause said bits to tilt or expand.

The invention consists, further, in the constructions and combinations of parts hereinafter described, and particularly set forth in the claims.

The invention will be more readily understood by reference to the accompanying drawings, forming part of this specification, in which- Figure 1 is a side elevation of an underreainer constructed in accordance with the invention. Fig. 2 is a central vertical sectional view of the same, showing the bits or slips in expanded or operative position and below the end of awell-tube. Fig. 3 is a similar view showing the bits or slips in extreme contracted position. Figs. 4 and 5 are respectively side and edge views of one of the bits or slips, sometimes calle( cutters Fig. 6 is a cross-sectional view on the line 6 6 of Fig. 2.

As shown in the drawings, 1 designates the underreamer, which consists of a suitable mandrel or body portion 2, having a central longitudinal bore 3, which bore is preferably of two diameters to provide a shoulder 20. The lower end of the mandrel of body 2 is provided with a central chamber, the lower portion 4 of which is preferably cylindrical in form and the upper portion 6 of which is in the form of a tapering socket or tapering chamber. The walls of the two chambers 4 and 6 are connected together by a beveled surface or abutment 4, which lies between the termination of the 'straight wall of the cylindrical chamber 4 and the inclined or conical wall of the chamber 6. The lower end of the wall of the chamber 4 is preferably beveled or inclined outwardly'toward the outer edge of the body portion, as shown at 7. On the upper end of the mandrel or body portion 2 is formed a reduced tapering end 8, which is provided wi th screw-threads, whereby the same may be connected with the usual sub or string of oil-well tools.

9 represents the bits or slips, the upper portions of which when brought together conform to the shape of the chambers 4 and 6. These bits or slips are composed of the bits proper, adapted at all times to extend bebelow the mandrel, and the shanks, adapted to extend within the mandrel. As shown,

the Shanks are composed of semicylindrical portions 9, the lengths of which correspond with the length of the cylindrical chamber 4,

IOO

outward at the junction of the portions 9" and the cutting portions ol the bits, so as to form shoulders 10, adapted to engage the end of the mandrel and abut thereagainst, so that the impact of the blow when the underreamer is in use is carried not only by the end of the mandrel, but on the shoulders 4 and .on the shoulders 4, formed at the top ol the conical chamber 6, thus distributing such impact throughout the body or mandrel 2 and preventing` the localization of such strain, and by thus distributing this strain the tendency of such strain to split the mandrel is reduced to a minimum.

The outer laces ol the bits are preferably curved or rounded, as shown, to correspond with the arc of the enlarged hole, so as to provide a rounded hole of increased diameter under the casing. The inner wallsv of the bits 9 are cut or beveled inwardly toward the center, thereby Jforming between said projecting ends when the cutters are assembled means for cutting the dirt or mud which might be caught between the collapsing bits and squeezing the same out Vfrom the sides oi the cutters, so that the bits may readily collapse and be brought together. The shanks of the bits or slips 9 are provided on their in-y ner faces with channels 12, at the lower ends of which are formed inwardly-projecting recesses 13, the lower wall of the recesses 13 being beveled or inclined upwardly and inwardly, as shown at 14, so that when the cutters or slips are brought together the channels 12 will form a cylindrical bore or passage communicating at its lower end with the circular triangular-shaped chamber formed by the recesses 13, which is provided for the reception of the head 15 of the spring-actuated rod 15.

At the upper end of the rod 15 and about the same I provide a sleeve 18, and between the lower end of this sleeve and a shoulder or abutment 2O in the body 2 is provided a coilspring 19, which encircles or is coiled about the rod 15. r1`he upper end of the rod 15 is threaded and adapted to receive a retainingnut 16, provided with an annular collar or ilanO'e 17. By the adjustment of the nut 16 on the rod 15 the required compression of the spring 19 is secured, so that such spring actuates to throw the rod 15 in the position of Fig. 2 and automatically carries the bits or slips 9 into the expanded or operative position. In fact, the position of the bits shown in Fig. 2 is the normal position thereof, being the position that the same will assume when the underreamer is not in use or has been allowed to descend through the well-casing and below the same. It will be noted that while the action ofthe spring 19 and rod 15 is to automatically draw the bits or slips 9 up into the chamber or socket ofthe mandrel and automatically expand the bits, yet none of the strain or impact on the bits while underreaming is borne by either the rod or spring, but is borne by shoulders or abutments 4 4 and the end of the mandrel from the shoulders 10 of the bits.

When it is desired to contract the bits so as to permit of the insertion of the underreamer in the well-casing and the lowering thereof through the casing to underream below said casing, the bits 9 are drawn down into a contracted position in the usual manner and held in contracted position in the usual manner, as by a segmental ring of the ordinary construction slipped about the contracted bits and holding them from eXpansion while they are being inserted in the top of the casing, this segmental ring being taken oil as soon as the bits are started in the casing and the cylindrical surfaces of the bits then contacting with the inner surface oi the casing.

In order to prevent the edges of the bits 9 from perforating the casing during the descent of the underreamer, it is preferable to provide the cylindrical surfaces 9 with a slight pitch, so as to throw the edges of the bits away from the casing. This, however, is common in underreamer-bits. By providing the nuts 16 with an annular collar or iiange 17 the downward movement of the plungerrod 15 is limited by the engagement of said collar with the upper end of the mandrel 2, thereby preventing the engagement of the cutting members or bits 9 from the head 15 of the spring-actuated rod 15, which disengagement would result in loss of the bits in the well. It is thus seen that by the provision of tapering shoulder 4 in the chamber 4 and the provision of inclined or beveled shoulders 9a on the bits means are provided for causing the tilting of the bits from their collapsed or contracted position to their eX- panded or operative position.

I/Vhile I do not coni'ine myself to the use of the tapering or cylindrical sockets 6, I prefer to use the same.

Other changes in details of construction and arrangements may be resorted to with- ,out departing from the principle of my invention, and I do not limit myself to the details of construction herein shown and described.

By thus providing a tilting abutment or surface 4 within the chamber of the mandrel and providing bits or-slips pivotally or tiltingly supported by the spring-actuated rod I secure the positive automatic expansion of the bits to underreaming position when the rod is permitted to slide upward in the man- IOO IIO

IIS

drel. This construction also permits the use of bits so constructed and of such form as to abut against the walls of the chambers of the mandrel and take all the concussion or impact (when the underreamer is in use) off of the spring-actuated rod and the pivot key or head holding the bits, thereby eliminating all danger of breaking such parts. j

By making the head 15 of the spring-actuated rod 15 in the `form of an arrow-head and providing in the bits or slips 9 sockets or recesses 13, corresponding in form to the wings of the arrow-head, I provide for the tilting action of the slips or bits and for a strong supporting head or pivot 1.5 without necessitating removal of sufficient material from the bits to weaken the same, and in the manufacture of oil-well tools great strength is essential.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. An underreamer of the class described comprising a centrally-bored mandrel having a cylindrical recess in its lower end,` a recess above said cylindrical recess, a beveled shoulder between said upper recess and said cylindrical recess, a rod movable longitudinally in the bore of the mandrel and having a head on its lower end and a pair of cutters recessed on their opposing inner sides to receive the lower portion oi said rod and the head of said rod, each of said cutters having a semicylindrical portion of a diameter to fit in the cylindrical recess of the mandrel, a semiconical upper portion to it in the upper recess of the mandrel, a beveled shoulder to engage the upper beveled shoulder of the mandrel, a lower portion of a diameter exceeding that of the cylindrical recess of the mandrel, a beveled shoulder between the semicylindrical portion and the said portion of enlarged diameter, the said portions of enlarged diameter having their inner opposing sides oppositely beveled to form wedgeshaped openings between them.

2. An underreamer comprising a centrallybored mandrel having a cylindrical recess in its lower end and a recess above said cylindrical recess, a beveled shoulder or abutment between said recesses, a spring-actuated rod slidable in said central bore, said rod having a head at its lower end, tilting slips tiltingly mounted on said head, said slips provided with cutting edges and with shoulders adapted to contact with said beveledshoulder or abutment.

3. An underreamer comprising in combination a centrally-bored mandrel having a cylindrical recess in its lower end and a second and smaller recess above said cylindrical recess, an inclined or beveled shoulder or abutment being provided between said recesses, a spring-actuated rod slidable in said mandrel, said rod provided with a pivot-head and underreaming bits or slips tiltingly mounted on said head, said bits provided with underreaming-faces and with shanks adapted to extend up into said recesses, said shanks having reduced upper portions adapted to iit within the upper recess.

4. An underreamer comprising a hollow' mandrel, a spring-actuated rod slidable therein, said mandrel having at its lower end a cylindric'al chamber and an inner and smaller chamber above said cylindrical chamber, an inclined or beveled abutment formed between the adjoining ends of the walls of said chambers, reaming-bits mounted on said rod and. provided with surfaces adapted to contact with said inclined shoulder or abutment to tilt said bits.

5. An underreamer comprising a mandrel having a recess 0r chamber in its bottom and an inclined or beveled abutment in the said chamber, aspring-actuated rod slidable in said mandrel, said spring-actuated rod havinga head oi a form similar to an arrow-heads tilting slips or bits having sockets corresponding to the wings of said arrow-head into which said arrow-head is adapted to fit, said slips or bits provided with shanks adapted to be drawn up into said chamber and provided with inclined shoulders adapted to abut against said beveled or inclined shoulders in said chamber to tilt said slips or bits on said arrow-head as said slips or bits are drawn inward into said chamber.

6. An underreamer comprising a hollow mandrel furnished in its lower end with a chamber provided at an intermediate portion with an inclined. or beveled portion or abutment, a spring-actuated rod sliding through said chamber and extending up in said mandrel, two jaws pivoted to said rod respectively Jfurnished at their upper ends with shanks extending above the pivot and into said chamber and furnished at their intermediate portions and above said pivot with inclined shoulders adapted to contact with said inclined abutment in said chamber,

7. An underreamer comprising a hollow mandrel furnished in its lower end with a chamber provided at an intermediate portion with an inclined or beveled portion or abutment, a springactuated rod sliding through said chamber and extending up in said mandrel, two jaws pivoted to said rod respectively furnished at their upper ends with shanks extending above the pivot and into said chamberiurnished above said'pivot 'with inclined shoulders adapted to contact with said inclined abutment in said chamber, said shanks of said bits being of suiiicient length to abut against the surface of the end wall of said chamber.

8. An underreamer comprising a mandrel provided in its lower end with an inwardlyextending chamber or socket, said chamber provided intermediate its length with an in- IOO IIC

clined or beveled abutment, a spring-actuated rod slidably mounted in said mandrel and extending through said socket or chamber up into the mandrel, two slips or bits pivoted to said rod and respectively furnished at their upper ends with shanks extending above the pivotal point to enter the upper end of said socket or chamber, said bits provided above said pivotal point with inclined shoulders adapted to abut against said inclined abutment in said socket or chamber to tilt said bits, said bits also provided with shoulders adapted to abut against the end of vsaid mandrel.

9.' An underreamer comprising a centrallybored mandrel having a cylindrical recess in its lower side and a recess above said cylindrical recess, a shoulder or abutment between said recesses, a spring-actuated rod slidable in said central bore, said rod having a head at its lower end, tilting slips tiltingly mounted on said head, said slips provided with cutting edges and with inclined or beveled shoulders adapted to contact with said shoulder or abutment.

10. An'underreamer comprising in combination a mandrel having a cylindrical chamber in its lower end and a tapering chamber above said cylindrical chamber and forming an inward extension thereof, a springactuated rod slidably mounted in said mandrel and extending up from said cylindrical chamber into said mandrel, reaming bits or slips tiltingly mounted on the lower end of said rod, said bits or slips having shanks extending above said lower end of said rod, said Shanks having tapered upper ends corresponding to said tapered chamber, said bits or slips adapted to contact with the walls of said chambers and provided with shoulders adapted to contact with the end of said mandrel when said bits are in operative position.

11. An underreamer comprising a mandrel, a spring-actuated rod slidable therein, said mandrel having at its lower end a cylindrical chamber and an inner and smaller chamber above said cylindrical chamber, an abutment formed between the adjoining ends of the walls of said chambers, reamingbits mounted on said rod and provided with surfaces adapted to contact with said abutment to tilt said bits.

12. An underreamer comprising in combination a mandrel having a cylindrical chamber in its lower end and a tapering chamber above said cylindrical chamber and forming an inward extension thereof, a spring-actuated rod slidably mounted in said mandrel and extending up from said cylindrical chamber into said. mandrel, the end of said rod in said cylindrical chamber being formed in the shape of an arrow-head, reaming bits or slips having sockets to receive the wings of said arrow-head and tiltingly mounted thereon,

said bits or slips having shanks extending above said lower end of said rod and into said tapering chamber, the upper ends of said shanks being tapered to correspond to said tapered chamber, said bits or slips adapted to contact with the walls of said. chambers an d abut against the end wall of said tapered chamber and provided with shoulders adapted to abut against the end of the mandrel ,when in operative position.

13. An underreamer comprising a centrally-bored mandrel having a cylindrical chamber in its lower end and a recess above said cylindrical recess, a beveled or inclined shoulder or abutment formed between said recesses, a spring actuated rod slidably mounted in said central bore, said rod having an arrow-head-sh aped end in said cylindrical chamber, bits or slips having sockets corresponding'to and adapted to receive the wings of said arrow-head and having shanks extending up into said cylindrical chamber and recess thereabove and provided with shoulders to abut against said abutment, said bits or slips abutting against the end wall of said recess when in operative position.

14, An underreamer comprising in combination, a mandrel, a spring-actuated rod slidable therein, said mandrel having in its lower end a cylindrical chamber and an inner and smaller chamber above said cylindrical chamber, an inclined or beveled abutment formed between the adjoining walls of said chambers, said rod provided with an arrowhead-shaped end, reamingbits provided with sockets corresponding to and adapted to receive the wings of said arrow-head and thereby tiltingly supported on said rod, said bits provided with surfaces adapted to contact with said inclined shoulder or abutment to cause the bits to tilt.

15. An underreamer comprising a Inandrel provided in its lower end with an inwardly-extending socket or chamber, said chamber provided intermediate its length with an inclined shoulder or abutment, a spring-actuated rod slidably mounted in said mandrel and extending through said socket or chamber up into the mandrel, two slips or bits pivoted to said rod and respectively furnished at their upper ends with Shanks extending above the pivotal point to enter the upper end of said socket or chamber, said bits or slips provided with inclined shoulders above said pivot-point to abut against said inclined abutment in said socket or chamber to tilt said bits.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

FREDERICK W. JONES. l/Vi tnesses:

D. W. HUFFMAN, ARTHUR H, BLANCHARD. 

